why didnt i study this in five years of thermodinamics

[raaaid]

whats the internal energy difference for 5 º
around 2000 J/kg in the best case

around 5000 j/kg in the worst case


U variation=Q-W
2000=Q-100


Q=2100


eficiency=w/q=100/2100=4.7% eficiency
in the worst case: 100/5100=2%

maximum eficiency for carnot?


1-cold focus/hot focus=1.3%